Light travels in empty space but if it is a transverse wave, how can it do that? Sound is also a wave, but there is no sound in empty space because there are no air molecules to transmit it. Yet light from the sun and stars still reaches us across the emptiness of space, so how can a wave travel without a medium to transmit it?
Consider the simple example of a wave travelling across a pool surface. The wave moves because the water moves, but a cork floating on it just bobs up and down as waves pass it. The waves don’t push the cork along because the water doesn’t move in the wave direction, it moves up and down. What moves as a wave isn’t the water, but it’s up-down surface displacement, so when a pebble drops on a still pool, that displacement spreads as ripples. Ripples spread when a surface vibrates, so shouldn’t light be the same?
A transverse wave vibrates at right angles to its movement direction. Water waves are transverse waves because the water moves vertically as the wave spreads horizontally. Light is also a transverse wave but in three dimensions not two. It is said to have no medium because materialism sees empty space as nothing at all, but if space is a surface, then light could be vibration on space.
The theory of relativity supports the idea that our space is a surface, because it lets space curve, and complex number theory also lets light vibrate into a dimension outside space. If these theories are correct, then space is a surface that can host light as a transverse wave. Light can travel in a vacuum, so it either vibrates nothing at all, which denies how waves work, or it vibrates something. The simplest option is that light is a vibration on the surface of space itself.
Why then don’t we see light waves moving up and down as water waves do? We know that light vibrates, but a ray of light seen from the side can’t be seen to move up or down. This is expected, as everything we see is based on light, so if light is sequestered to our space (Randall, 2005), we can’t see what happens outside it. A transverse wave can’t leave the surface it vibrates on, so light can’t move outside space, but reverse engineering can deduce that it vibrates on space.
What then moves when light moves? According to physical realism, nothing does, but the alternative is that the quantum network does. Maxwell’s equations describe light as an electromagnetic wave that vibrates orthogonal to space. Let this vibration be the quantum network setting a transverse circle of positive and negative displacements on the surface of space. If this circle completes at the same point in one cycle, the displacements cancel out to give empty space, but if it is distributed over two or more points, it is a wave of light (Figure 2.7). Chapter 3 gives more details, but essentially light is a positive-negative surface displacement, just as water waves are. What moves when light moves is then quantum processing.
The waves spreading on the quantum network are quantum waves, with light as their simplest form, but what actually are they? Schrödinger called quantum waves matter density waves, because high values make matter more likely to exist there, but quantum waves aren’t made of matter. Born called them probability waves, because their amplitude squared at a point is the probability that matter exists there, but a probability is just a number. We expected the ultimate reality to be made of matter, but instead found just numbers. The quantum waves that predict physical events have no mass, momentum, velocity, or any other physical property, but they are waves that can manifest as space, light, or matter.